Mr. Clemons proposes to determine the crystal structure of a small ribosomal protein, S15, from Bacillus stearothermophilus, to crystalize and solve the structure of the complex of S15 with its minimal binding site of 16S ribosomal RNA, and to crystalize initiation factor If2 alone and in complex with the initiator. He proposes to design a suitable rRNA as a target substrate for S15 binding. How this will achieve the same binding efficiency for s15 as native rRNA is not clearly described. The last goal of this proposal will be accomplished by a collaboration with Dr. U. RajBhandary from MIT, who will provide purified forymlmethionine charged initiator tRNA. The significance of studies that will be applied for understanding the biological functions of these proteins, is not described.